diff options
Diffstat (limited to 'EDK/Foundation/Library/EfiCommonLib/x64')
-rw-r--r-- | EDK/Foundation/Library/EfiCommonLib/x64/EfiCopyMemRep4.asm | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/EDK/Foundation/Library/EfiCommonLib/x64/EfiCopyMemRep4.asm b/EDK/Foundation/Library/EfiCommonLib/x64/EfiCopyMemRep4.asm new file mode 100644 index 0000000..62e377c --- /dev/null +++ b/EDK/Foundation/Library/EfiCommonLib/x64/EfiCopyMemRep4.asm @@ -0,0 +1,65 @@ +;------------------------------------------------------------------------------ +; +; Copyright (c) 2007, Intel Corporation +; All rights reserved. This program and the accompanying materials +; are licensed and made available under the terms and conditions of the BSD License +; which accompanies this distribution. The full text of the license may be found at +; http://opensource.org/licenses/bsd-license.php +; +; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, +; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. +; +; Module Name: +; +; EfiCopyMemRep4.asm +; +; Abstract: +; +; CopyMem function +; +; Notes: +; +;------------------------------------------------------------------------------ + + .code + +;------------------------------------------------------------------------------ +; VOID +; EfiCommonLibCopyMem ( +; OUT VOID *Destination, +; IN VOID *Source, +; IN UINTN Count +; ); +;------------------------------------------------------------------------------ +EfiCommonLibCopyMem PROC USES rsi rdi + cmp rdx, rcx ; if Source == Destination, do nothing + je @CopyMemDone + cmp r8, 0 ; if Count == 0, do nothing + je @CopyMemDone + mov rsi, rdx ; rsi <- Source + mov rdi, rcx ; rdi <- Destination + lea r9, [rsi + r8 - 1] ; r9 <- End of Source + cmp rsi, rdi + jae @F + cmp r9, rdi + jae @CopyBackward ; Copy backward if overlapped +@@: + mov rcx, r8 + and r8, 3 + shr rcx, 2 + rep movsd ; Copy as many Dwords as possible + jmp @CopyBytes +@CopyBackward: + mov rsi, r9 ; rsi <- End of Source + lea rdi, [rdi + r8 - 1] ; esi <- End of Destination + std ; set direction flag +@CopyBytes: + mov rcx, r8 + rep movsb ; Copy bytes backward + cld +@CopyMemDone: + ret +EfiCommonLibCopyMem ENDP + + END + |